Rotary pump and motor hydraulic transmission



Nov. 10, 1953 D MCCHLL 2,658,343

ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed May 17, 1949 8Sheets-Sheet l //\/Z/E/\/ TU DANIEL F: mam

fl Tru A/e W5 Nov. 10, 1953 o. F. M GILL ROTARY PUMP AND MOTOR HYDRAULICTRANSMISSION 8 Sheets-Sheet 2 Filed May 17, 1949 fl TTURNE W5 Nov. 10,1953 F, MCGILL 2,658,343

ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed May 17, 1949 8sneets-shet 3 ,4 TTURNE/E Nov. 10, 1953 o. F. M GI LL 2,658,343

ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed May 17, 1949 8Sheets-Sheet 4 flTTUR/VE V5 Nov. 10, 1953 D, F, MCGILL. 2,558,343

ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION File M y '7, 1949 8Sheets-Sheet 5 /NL/ENTUF DANIEL F. N

Nov. 10, 1953 D. F. M GILL ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSIONFiled May 17, 1949 8 Sheets-Shee't '7 N1! MR 5% g m Na 3 sfi 8 h VW\EEJWW R g QR mm 8w P 5 Q R t Rm M \R vm L? f; I a W I NR 3 l a; H

//\'/z/E/\/TUF? DANIEL F. MGILL EM gym/QM v NE 24 TTURME W5 Nov. 10,1953 NZ/EN TUE a TTUR/VEWE Patented Nov. 10, 1953 ROTARY PUMP AND MOTORHYDRAULIC TRANSMISSION Daniel F. McGill, Portland, reg., assignor toDonald W. Green, Portland, 0reg., as trustee Application May 17, 1949,Serial No. 93,691

17 Claims. (Cl. 60-53) This invention relates to a transmissionmechanism for transmitting power through a fluid medium from a drivingshaft to a driven shaft in different speed and torque ratios.

The general objects of the invention are to provide a compact andeflicient transmission which avoids the losses inherent in mostconventional fluid transmissions and which is capable of transmittingpower in certain definite driving ratios as well as an infinite numberof other ratios.

An important object is to provide a fluid transmission in which theentire input torque of the driving member is directly applied to thedriven member throughout all lower speed ratios as Well as in a director 1 to 1 speed ratio.

Particular objects are to provide a positive displacement type of fluidtransmission wherein the driving and driven shafts are positivelyinterconnected in different driving ratios by an incompressible fluidmedium without slippage, and to provide a positive displacement fluidtransmission having reaction members mounted concentrically with drivingand driven members to rotate as a unit with the driving and drivenmembers in direct drive without any relative movement between thedifferent parts of the transmission and without any pumping of fluidtherein. Another object is to provide a transmission of the typedescribed in which different ranges of driving ratios, and direct drive,are established by operation of a novel valve mechanism whichselectively controls or prevents the circulation of the transmissionfluid, and in which the actual torque ratio at any instant may adjustitself automatically in response to the load, within the limits of therange of ratios determined by the position of the valve mechanism.Another object is to provide a transmission having a variabledisplacement component with a plurality of reaction chambers which maybe included in the fluid circuit in variable number to apply torque tothe driven member in addition to the torque applied directly by thedriving member.

Further objects art to provide a transmission mechanism of the typedescribed in which the desired torque may be transmitted withoutbuilding up excessive fluid pressures to provide a mechanical design inwhich the outer sealing means are not subjected to the fluid pumping.pressures in the transmission, and to provide novel and improvedsealing means for the rotary parts within the transmission.

A still further object is to provide an automatic control mechanism foruse on an automotive vehicle or other application involving an internalcombustion engine for changing the driving ratios of the transmissionunder the different conditions encountered in use to eiiect an entirelyautomatic transmission.

Three embodiments of the transmission are disclosed. In each embodimentthere is a driving member, a driven member and a plurality of reactionmembers, all rotatably mounted and concentrically arranged so that theoutermost member serves as anexternal housing for the transmission anda. reservior to contain the transmission fluid. Direct drive is effectedby closing a control or ratio valve to prevent fluid circulation withinthe transmission so that all the members are caused to rotate in unisonto establish in effect a direct mechanical connection between thedriving and driven shafts, although in reality the connection is notmechanical but a hydraulic lock through the medium of the incompressiblefluid in the transmission,

which is preferably a suitable oil.

The driving and driven members in each embodiment cooperate to form apositive displacement pump component, the outlet of the pump chambersbeing through said control or ratio valve. Hence, as long as the ratiovalve remains closed, fluid cannot discharge from the pump chambers andthe pump members comprising the driving member and driven member of thetransmission cannot move relatively to each other, but are lockedhydraulically together so that they can turn only in unison.

The ratio valve is arranged to open a series of ports in succession asit is moved away from its closed position, and when it is opened topermit discharge. of fluid from the, pump chambers, the driving membermay then turn relative to the driven member according to the rate atwhich fluid is allowed to escape from the pump chambers. The differentports of the ratio valve admit the fluid from the pump component intoseparate chambers which may act aspositive displacement motor chambersof a fluid motor or reaction component to increase the torque applied tothe driven member in accordance with the pressures developed and theadditional piston areas exposed to such pressures. When the ratio valveis moved to admit fluid to all of the motor chambers through wide openports, the motor component is then operating at its maximum displacementand pressure to provide the lowest speed, highest torque, driving ratio.In certain intermediate positions of the ratio valve, only a part of allthe working chambers of the motor 3 component are included in the fluidcircuit to effect one or more definite intermediate driv ratios.

In other valve positions, when the fluid flow is throttled through someof the ports to reduce the pressure in the motor chambers, an infinitenumber of ratihs is possible, to nreviae smooth performahce through awide range of speeds and torques, and the manner in which this isaccomplished in a positive displacement device constitutes an importantfeature of the invention. Depending upon the valve position andassisting conditions, the pressures in the reaction chambers may varyfrom a vacutiiii 'i'jnditlhr'i tip to the pump chamber pressuretoaifbr'tlaiiovelty'pe of automatic load response and ratio control;which will be described in detail in connection with the differentillustrated embodimentser the invention. The parts are so arranged thateven in a speed ratio lower than 1 to 1 the entire input tor ue isalways applied directly to'the driven member.

In the preferred embodiment first illustrated on the drawings, thedriving member is outermost and forms the transmission housing andfii'iidreservolr, while the other embodiments disclose alternativearrangements in which the driv- "ing member may be either centrallydisposed or interposed between the driven'and reaction mem- Beis. Forcertain applications the control or ratio valve may be actuated manuallybut in the p: 'e'nt embodiments, for use with an internal bastionengine, automatic control mechanism is provided for this valvecomprising "springs, 'a speed responsive "governor on the driven shaftand a pressure responsive diaphragm connected with the intake manifoldof the engine, H I

The pre ent transn iissidn is intended only for "unidirectionalrotation. Where reverse rotation is also necessary, a reverse gearhavinga manual shifting lever is'interpose'd in the driven shaft.

These and other objects and advantages the invention will be apparentand the invention will be'better im'derstaed from the following descrip-'tion with r'ere'renee t the embodiments illustra'tedbn the accompanyingdrawings. It is to be iinde fstddd that various changes may be made inthe construction and arrangement of parts and "diat-ee'rta'm parts maybe used without others.

In'the flra'mngs i Figure 1 is a longitudinal sectional view of aeihbeaiinent er the invention in'which tl'ieo'uter'member is'the drivingmember and the hrtermediatememBer is 'the driven member, this j iicwalso inclnd'ing control mechanism to make the transmission fullyautomatic for use in an automobile;

Figure 2 isa cross sectional view taken on the 'line"2'-2 o'f-Figure 1;Figure 3 is 'a fragmentary sectional view thmughthe valve mechanismtaken on the line 3-8 of Figure 2; 7

Figure 4-is' afragmentary sectional view of one of the radial bladesshown in Figure 2 mechanism of Figures 1 and 11in rest position;

Figure '8 is a "diagram showing "the control mechanism in direct "driveat normal speed;

Figure 9 is a diagram showing the control innermost member is thedriving member and the intermediate member is the driven member;

Figure 12 is a cross sectional view taken on the line I2l2 of Figure 11;

Figure 13 is 'aiienlarged fragmentary sectional view of the ratio andneutral valves taken on line ia ltef riigurejm;

Figure 14 is an enlarged fragmentary sectional view of one of theannular sealing rings shown in Figure 11;

Figure 15 is a perspective view of a portion of the sealing ring shownin Figure 14;

Figure 16 is a fragmentary view showing the centrifugal governor deviceand ratio control lever of Figure 11 at normal, or high, speeds indirect drive, corresponding to the diagram in Fieu fl;

Figure 17 shows the ratio lever drawn back out of direct drive positionby operation of the solcnoid as in Figure 10; c c

Figure 18 isan enlarged sectional view of the driving member andauxiliary pump shown in Figure 11; c

Figure 19 is an enlarged sectional view of the auxiliary pump valvetaken on the line lS-IS of Figure 18; V

Figure 20 is a, view corresponding to Figure 19 showing the valve in adiiferent position;

Figure -21 is a longitudinal sectional view of a third embodiment oftheinvention in which the intermediate member is the driving member andthe outer member-is the driven member; I

Figure 22 is a cross sectional view taken on the line 22-22 of Figure21; and

Figure23 is a fragmentary sectional view taken on the line 23-;4-3 ofFigure 22, showing the ratio and neutral valves. A

In its three different forms the invention is embodied in an automatictransmission for use in an automobile to'take the place of theconventional clutch and sliding gear transmission. Suitable controlmeans are disclosed to adapt the transmission to the special needs ofautomotive use, but it will be readily apparent to persons skilled'inthe art that the transmission is capable of general application, andthat other suitable automatic control means or manual control "means-maybe applied to the transmission.

Preferred monument airwaves 1 and z In Figure 1 the numeral "designatesthe rear end 'of the block or other stationary partfoi the internalcombustion engine of an automobile, and the-numeral I the crank shaftof'the engine. The nuineral I2 designates the driven shaft of thevehicle whereby in reference to the present transmission the 'sha'ftl lis the driving shaft and the sheftflz, whie'h' is in axial alignmenttherewith, is the driven shaft. The crank shaitor drivi hg shaft H isequipped with a flange II which is bolte'd't'o "the driving member it ofthe transmission, and this driving member equippedwith a ring gea isotthe type which is usually mounted on the engine flywheel to be engagedby the pinion gear on the "motor. The driving member i5 is preferablymade in twoparts having mating flanges 19 which may be bolted tightlytogethertoiorm a rotatable housing and mud reservoir for thetransmission, and this housing may serve'as the flywheel for the engine.

a The housing I5 is equipped with a drain plug 2| and a filler plug 22.A filler tube 23 extends into the housing a depth from the filleropening to establish the proper liquid level in the housing when it isfilled. When the filler opening is uppermost, as shown in Figure 1, thelower end of the tube 23 preferably extends some distance below the axisof the housing so that the trapped air above this level will occupysubstantially more than half the free space in the housing. Thetransmission requires a relatively small amount of liquid in thereservoir, which liquid is distributed around the periphery of thehousing in a ring of uniform depth as long as the crank shaft H isrotating.

The forward end wall of the housing [5 adjacent the crank shaft flangel3 contains a bearing 25 to support the forward end of the driven shaftI2. Secured to the engine I is a stationary housing 26 carrying a plate21 which has a sleeve 28 surrounding the driven shaft l2 and extendinginto the rear end of housing l through a bearing hub 29.

The principal parts of the transmission in relation to the fluid mediumcomprise an annular member 30 secured to the housing l5 and forming anintegral part of the driving member, a driven member 3| secured to thedriven shaft l2, and three separate reaction members 32, 33 and 34. Themember 30 is fixed to the housing l5 by means of a key 35 or suitablesplines and may be considered as the driving member of a fiuid pump.Driven member 3| comprises three rings or annular parts 36 clampedbetween four radial plates 31 as shown in Figure 1. These rings andplates form a cylindrical surface on their outer periphery to have arotating fit within the driving member 30 which has cavities definingthree chambers 38 around the driven member 3|. The chambers 38 aredesignated as pump chambers because upon relative rotation of thedriving and driven members fluid from the reservoir of the transmissionhousing is drawn into these chambers and pumped out under a workingpressure.

Within the rings 33 the plates 3! define additional sets of chambersreferred to as motor chambers because they ma be connected to receivethe fluid pumped from the pump chambers to drive the driven member.Between the front end plate 31 and the next intermediate plate 31, thereare three motor chambers 42 disposed symmetrically around the interiorof the driven member; The two intermediate plates 31 constitutepartitions enclosing a central set of three motor chambers 43, and oneof these plates and the rear end plate 3! constitute end walls foranother set of motor chambers 44. These motor chambers comprise cavitiesin the rings 36, as shown in Figure 2 in the case of the centralchambers 43.

Each space between the plates 31 contains one of the reaction members32, 33 and 34, the reaction member 33 being shown in Figure 2. Thereaction members 32 and 34, and the chambers 42 and 44 in which theyoperate, do not appear in Figure 2. Each of the reaction members 32, 33and 34 is provided with a set of spring biased one-way brake dogs orwedges 45 engageable with stationary sleeve 28 to permit free rotationof that reaction member in the direction of arrow 46 and prevent reverserotation whereby some of the reaction members may rotate while othersremain stationary undercertain working conditions of the transmission;The arrow 45in Figure 2 designates the direction of rotation of all therotatable parts of the transmission. This direction'will be referred toas the forward direction. No part of the transmission turns counter tothis direction.

Between the cavities in the driving member 30 which form the three pumpchambers 38' between this member and driven member 3|, the drivingmember has three fluid abutments 55 extending inwardly to make arotating fit with the outer periphery of the driven member 3| and formpartitions between the pump chambers. The outer periphery of drivenmember 3| is slotted longitudinally to receive a plurality of seals 5|arranged to prevent leakage from one chamber 38 to the next between thedriving and driven members. The specific form of these sealing membersis shown in Figure -5. Each seal 5| is molded of a suitable resilientmaterial which will not deteriorate in the presence of hot oil. The sealis in the form ofa bar having a wide base to fit in a wedge-shaped slotwith its upper edge surface or lip 52 flush with the surface of thedriven member. Below the top surface 52 there is a step surface 53 and avertical surface 54 having a combined area greater than the rubbing areaof surface 52.

When these surfaces of the seal are exposed to fluid pressure'in thechambers 38, the pressure acting on the greater area of surfaces 53 and54 tends to compress the body of the material against the bottom andside walls of the slot, causing the surface 52 to rise and projectslightly above the surface of the driven member. Hence, the surface 52under such conditions will engage the arcuate inner surface of thepartitions 50, the sealing effect being greater under greater pressure.When the pressure in chambers 38 is reduced, the seals 5| return totheir original relaxed shapes in which they have only light contact withthepartitions 50. With the use of such seals, the sealing pressure anddrag on the parts never exceeds the value necessary to prevent leakage,and the abutment partitions 50 can be made relatively short, therebyallowing for the three pump chambers Without requiring the ramp surfacesto slope too abruptly.

Driven member 3| also carries a plurality of radial blades 55 mounted inslots 56 as shown in Figure 4. Springs 51 urge the blades outwardly intolight contact with the interior surface of driving member 30 to followthe contours of chambers 38 and partitions 50. One wall of each slot 56on the pressure side of the block contains a groove 58 to communicatechamber pressure to the bottom of the blade slot to assist the spring 51in extending the blade out of the slot when the chambers 38 are underpressure. This arrangement will produce an outward bias on each bladeproportional to chamber pressure, because the full chamber pressure iseffective over the full area of the bottom ofthe blade, whereas'it isnot effective over the whole area of the outer end of the blade. Whenthe pressure is reduced in the chambers 38, the fluid pressure bias onthe blades is also reduced to avoid unnecessary friction and wear. Thesprings 51 need only be strong enough to extend the the direction ofarrow 46 relative to driven member 3|, it will'be apparentthat theeffect is the same as rotating member 3| as a pump rotor in the reversedirection, causing the blades to sweep 7 thromhtheehamberslltamawinfluidthrough inlet ports; SI and discharge it under pressure through outletports.- 6t.. It be observed that. as. a partition 50 encounters a seal,such as the seal Sta inFigm'e. 2', the seal surfaces 53 and 54 remain incontact: with. the chamber pressure to raise. the. lip surface; 52 onto!the. slot and into. sealing engagement withthe arcua-tesurface ofpartition 50, so. thatv the blades 55 are. not required to bear against.the. partition surfaces with sufllcient force to make an eflective. sealthemselves. It will also. be apparent that the source of pressure is:removed from each groove I as soon asthe trailing side of outlet port.6|

starts to pass the blade, whereby the fluid pressure acting radiallyinwardly on the outer end or theblade becomes eflectlveto retract theblade partially, or at least to reduce its rubbing pressure and reducefriction on the surfaces of. partitions 50.

Fluid forced out of each outlet port 8| by the relative rotation ofdriving member 30 and driven member 3| flows through radial passages 42and circular channel 630 to a longitudinal. passage. 83 having ports 84and 45 leading to the longitudinal cylinder 66 of a balanced pistonvalve10. This valve is designated as a ratio valve because it operates tocontrol the driving ratio of the transmission. In Figure 3. the ports 64and 65 do not appear in the plane of the view, but the relativelongitudinal positions of these ports are indicated by dotted lines.Ports l2, l3 and 14 establish communication between the valve cylinder66 and the respective motor chambers 42, 43 and 44 associated with thereaction members 32, 38- and 84. There are three valve assembliesidentical with the valve assembly shown in Figure 3.

Each reaction member is equipped resilient seals- UI and blades 55 whichoperate in the same manner as the blades and seals in driven member 3|hereinabove described.

In Figures 2' and 3 the ratio or piston valve 10 is shown: at its; limitof: forward travel in which the ports 64, 12", I8. and 1.4 are closed,the port 65 being open but cut oil from communication with any otherport. In this position of the valve Ill it is apparentthat fluid cannot.be discharged from theoutlet ports Si in the pump chambers, and hence,sincethe fluid is. an incompressible medium, the. driving member 30cannot rotaterelative to the driven member 3|. The ratio valvev III isthereby effective in its Figure 1 and 3 positions to lock hydraulicallythe driven member 3| to. the driven member I5, 30 and establish theequivalent of a direct mechanical connection between the drive shaft anddriven shaft, although, in. fact, the transmission fluid confined in.the. pump chambersv 38 constitutes one, link of this connection.

When the ratio valve 10 in Figure 3 is moved rearwardly, in the.direction of. arrow 15, the. port 12 to a. motor chamber 42 is openedand placed incommunication with port 65. In a similar manner, each ofthe other two pump chambers 42, has an inlet port I2 communicating with.one of. the other. two valve cylinders 66. Fluid d'elivered underpressure through inlet ports 12 reacts against the. blades 55 inreaction member 32, tending to rotate the reaction member in a. reversedirection. which. rotationv is prevented oneswav brake. elements 45,.Hence. as fluid .issnumne dnto chambers. 42, the r v member ti whioh, ineiieohiormsthe casing, for tlnwchamheraia dnveaiomarddn. the dime- 8tion of 44 by an additional force depending upon. the pressure developedin chambers 42.

When the piston valve I0 is moved rearwardly a. greater amount,ituncovers ports 43- in addition to ports 12,, so that fluid deliveredfrom the pump chambers 38 is allowed to enter the three motor chambers43 aswellas the three motor chambers 42. The displacement or volumetriccapacity of the total number of motor chambers in the fluid, circuit isvthereby increased accordingly, and the driving force exerted on thedriven member is: increased in accordance with the pressure developed:in chambers 43. The fluid flow from pump chambers 38. to motor chambers43 can be traced directly in Figure 2, which is a sectional view showingthe central reaction member a and central. motor chambers 43, it beingremembered that fluid is also being delivered at the same time throuparallel ports and passages to the motor chambers. 42;

When the piston valve II is movedto its rearmost position, the. ports65', I2 and 13 remain open to. continue supplying the motor chambers 42and 43 and, in addition, ports 64 and I4 are uncovered to. supply thethird set of motor chambers 44 containing the reaction member 34, andapply additional. driving torque to the driven member by the action ofthe fluid pressure in chambers 44. This condition of operationrepresents the lowest speed. driving ratio and the highest mechanical.advantage obtainable by the transmission, wherein the displacement andpiston areas in the. nine. motor chambers 42, 43 and: M ar utilized tothe fullest extent.

The drive is positive. in a definite torque ratio in each of the threepositions of the valve 10 in which one or more of the ports 12, 13 and14 are wide open with no port throttled. Likewise, in direct drive, whenthe ratio. valve III is in the position shown in Figures 1 and 3, thereis, in effect, a definite positive driving connection in one-to-oneratio without slip between driving member 3|! and driven member 3|,because the fluid then cannot escape through outlet ports 6| in thepump-chambers 34.

When the ports I2, 13, 14 are all closed for direct drive, the rotationof driven member 4| would tend to draw a vacuum in the motor chambers42, 43, 44 and: exert a drag on the driven member were it not possiblefor the reaction members to rotate in a forward direction along withthedriven member. By reason of the fact that the three reaction membersare independent of 'each other, some of these members may remainstationary while others rotate when the ratio valve is moved tointermediate positions to admit fluid to some of the motor chambersandnot to others; The reaction members remain stationary only when reactionpressure is exerted thereagainst in the motor chambers to hold themstationary'against. their overrunning brake dogs. The motor chambersare, therefore, also referred to as reaction chambers.

When the. three ports 1'. are opened sufiici-ently to admit fluid to themotor or reaction chambers "fast enough to build up a pressure therein,the result of this pressure is to apply a forward driving. force or torue to the driven member 3| in addition. to the. torque applied directlyby the fluid. pressure in pump chambers 38. As the pressure in the motorchambers increases, either by reascnof wider opening of the ports 12 orby a. tendency for the driven. member to slow down under load, this.additional torque increasesautomatically. accordingto. demandto. carrythe load.

This condition may be described as a throttling or transition phase ofoperation wherein the additional torque obtained from a certain amountof valve opening depends chiefly upon the load on the driven member andvaries with the load to effect any necessary speed change smoothlywithin a definite range of torque ratios. The maximum amount of torqueincrease is obtained from chambers 42 when the three ports I2 are wideopen to maintain approximately the same pressur in chambers 42 thatexists in pump chambers 38, the torque ratio then being a function ofrelative piston areas in the pump and motor 'chambers, taking intoconsideration the different effective radial distances of these chambersfrom the axis of rotation.

When the ratio valves 10 are moved farther to begin opening the threeports I3, the torque applied to the driven member is further increased"by the establishment of fluid pressure in the chambers 43. This torqueagain increases with the reaction or motor chamber pressure through asecond range of ratios. Similarly, a further gradual torque increasethrough a third range of ratios is obtained as the ports M are opened tofill and establish pressure in the chambers 44. The operation of thevarious reaction chambers in the manner described does not affect thedirect application of torqu to the driven member in one-to-one ratiowhich takes places in the pump chambers.

Thus, notwithstanding the existence of certain definite or fixed drivingratios, the variations in the speed and torque ratios in response todiiferent valve positions and different load conditions are gradualthroughout the entire range of the transmission to provide smoothoperation under changing conditions. By providing a plurality ofreaction or motor chambers which may be brought into operation insequence the establishment of working pressures in the motor chambers iscaused to occur at a plurality of different speed ratios which areconvenient for the purpose. The chambers 42 may be enlarged and thechambers 43 and 4.4 eliminated without changing the principle ofoperation, but the arrangement shown is preferred as being moreefilcient for the present purpose.

Fluid is drawn into pump chambers 38 from the -'oil reservoir in housingI5 through inlet ports 00 disposed close to the periphery of thishousing, so that all of these ports will be submerged in the event thereis only a slight depth of fluid distributed uniformly around the housingwhen the latter is rotating. The fluid. is returned to the reservoirthrough outlet ports 82, 83 and 84 having free communication with alongitudinal discharge passage 85 which opens at both ends into thereservoir space Within housing I5. There is an outlet port 02 for eachof the three motor chambers 42, an outlet port 83 for each of the threemotor chambers 43, and an outlet port 84 for each of the three motorchambers 44. One set of these ports is shown in Figure 3, but they donot appear in Figure l. The three outlet ports 83 appear in Figure 2.

Each longitudinal channel 63 also has ports 86 and 8'! communicatingwith a cylinder 88 for a balanced neutral valve 93. The longitudinalpositions of these ports are indicated by dotted lines in Figure 3, but,like the ports 64 and 65, these ports are above the plane of the viewand do not actually appear in Figure 3. The positions of these ports arealso indicated at 85 in Figure 2. When the neutral valve is in itsrearmost position as shown in Figure 3, the ports 86 and 81 are closed,but when the valve 90 is moved to a forward position, communication isestablished between thes ports and other ports 92 in the wall oflongitudinal passage 85. The valve has only two positions.

' The three neutral valves 96 are attached to an actuating plate 95 andwhen this plate is moved forward in the direction of arrow 96 the outputof pump chambers 38 is emptied directly into the discharge passage andreturned to the housing reservoir without building up pressure in pumpchambers 38 and thereby not transmitting any driving torqu to drivenmember 3|. This valve remains closed at all times when the transmissionis used to drive the driven shaft I2, and is opened only to interruptthe connection be tween the driving and driven shafts.

The three ratio valves I0 are similarly connected with an actuatingplate Slwhich is movable rearwardly in the direction of arrow 15 todifferentpositions as hereinabove described.

In some uses of this type of transmission, it maybe desirable to permitoverrunning of the driven shaft, but in the present installation in anautomobile it is preferred to prevent such free wheeling. There areaccordingly provided a set of rocking wedges or dogs I00 between the endof the driven shaft I2 and the housing I5 operable in the manner of thewedges 45 in Figure 2 to serve as an overrunning clutch between thedriving and driven shafts. The dogs I00 are in- .clined in the samedirections as the dogs 45, but,

.a brake when the throttle is not depressed.

At the rear end of the transmission there is provided a single one-waybrake dog IOI arranged to prevent reverse rotation of driven shaft I2 toprevent the vehicle from backing down a hill.

This wedge device is preferably made releasable so that it will functiononly when desired. As shown in Figure 1, the dog IOI seats against theend of a pin I02 to function in the manner described, permitting forwardrotation of shaft I2 and preventing reverse rotation. The pin I02 is.held in its depressed position shown by a cam I03 connected with alever I04 for rotation on a transverse shaft I05. In the drawing, thelobe of cam I03 is turned downwardly to depress the pin I02 to theposition described. When the cam I03 is turned away from this position,the pin I02 may "be readily pushed back by dog IOI which is contained ina socket of greater depth than the .length of the dog sothat the shaftI2 can then rotate freely in either direction. This hill holding deviceis a convenience for automotive use, but is not essential to theoperation of the present transmission.

Control mechanism in Figure 1 The actuating ring 91 for ratio valve I0is attached to a cross bar M0 on the end of an axially slidable tube I II extending through the center of the hollow shaft I2. The rear end ofthis tube is connected with a cross head H2 in a ring I I3.

The longitudinal position of ring H3 and cross head I I 2 maybe shiftedby an outer non-rotating end of rod I20 is connected with a cross in aring I22. may be driven member 11 on the lower end of a shifting lever II inamanner well understood in the art and commonly used on clutch throwlevers. The upper end of shifting lever I I5 is pivotally mounted on afixed Pin II6.

Similarly, the actuating ring 95 for the neutral valve 90 is connectedwith a cross bar IIS on a rod I extending through the tube I II. Therear head I2I The ring I22 and cross head I2I shifted longitudinally onthe shaft I2 by means of an outer non-rotating ring I23 having pivotalconnection with a yoke at the lower end of a shifting lever .I24. Thecross bars H0 and H8 have longitudinal travel in a transverse slot I25extending through shaft I2 and the hub of 3I within the transmissionhousing, and the cross heads H2 and I2I have longitudinal travel in atransverse slot I26 to the rear of the transmission housing. The bore inshaft I2 contains suitable seals to prevent escape of the transmissionfluid.

The neutral lever I24 has a fixed pivot and manual operating handle, notshown. 'The ratio shifting lever II5 has pivotal connection at 129 witha rod I30. The forward end of the rod I30 is connected with a diaphragmI3I in a housing I32 which forms a vacuum chamber H3 in front of thediaphragm. Chamber I33 is connected with a vacuum line I 34 leading .tothe intake manifold of the engine. An adjustable threaded bushing I35having a lock nut I36 supports the rod I30 in the housing I32 andprovides arear stop or abutment fora diaphragm spring I40. This is acompression spring acting in conjunction with reduced pressure inchamber I33 to move the shifting lever H5 in a forward direction.Atmospheric pressure is in communication with the spring side of thediaphragm at all times, either by access through bushing I35 or througha vent in the rear side of the housing.

The rear end of rod I30 is connected with a reciprocating armature MI ina solenoid I42. The ener izing circuit for the solenoid is closed by aswitch I43 associated with the foot throttle of the automobile so thatthis circuit is closed when the foot throttle is pressed down as far asit will go. The switch retums to open position when the throttlepressure is released and it remains open in positions of the footthrottle assumed in normal driving.

A valve I45 is connected in the vacuum line I34. This valve is areciprocating balanced piston type valve having a piston element I46 ina cylinder in the valve body. The piston element I46 is normallyextended to hold the valve open for communication through line I34 by aspring I41 acting on the piston rod or valve stem I46. The pistonelement I46 may be retracted against the force of spring I41 tointerrupt communication through the vacuum line I34 by energizing thesolenoid I50. When the solenoid is energized, armature I5I on the pistonrod I46 is drawn into the solenoid to close the valve port communicatingwith the engine manifold. A notch I52 is provided in the piston elementI46 to admit atmospheric pressure into the valve port communicating withchamber I33 when the piston element is retracted in order to balance theair pressure on opposite sides of the diaphragm. Thus, when the solenoidis energiz d, the diaphragm is rendered non-responsive to reducedmanifold pressure.

Mounted on the shaft I2 9. distance ahead of the transverse slot I26 isa collar I54. Disposed between the collar I54 and the ring III are acompression spring 155 and a centrifugal governor device I56. Thegovernor device I56 comprises apair of end plates I51 interconnected bypairs of pivotal links I56 carrying fly weights I59. A secondcompression spring I60 is disposed between the two plates I51, urgingthem apart to retract the fly weights, as shown in Figure l. at lowrotational speeds of the shaft I2. The plates I51 are both slidablelongitudinally on the shaft I2, but they are constrained by splines orother means to rotate with the shaft. The maximum spacing of plates I51under the action of spring I60 may be adjusted by a pair of bolts I6Ihaving nuts I62, as shown in Figure 6. This adjustment determines thespeed necessary to throw out the governor weights.

The arrangement is such that spring I55, which may be identified as theshaft spring or ratio spring, urges the governor assembly I56 againstthe ring I I3, tending to shift the ring rearwardly toward ratio driveposition. Governor spring I60 is preloaded between the plates I51, andis of sufficient stiffness to prevent contraction of the plates I51toward each other by the action of spring I55 alone. The fly weightsI50, however, have sufficient mass to draw the plates I51 together andcompress the spring I60 to varying degrees with increasing speeds of theshaft I2 above a predetermined minimum value.

The operation of the control mechanism shown in Figure 1 will now bedescribed under the operating conditions in a motor vehicle driven by aninternal combustion engine, with reference to the diagrams in Figures '7to 10. The dotted shading in diaphragm housing I32 indicates thepresence of atmospheric pressure on one or both sides of the diaphragm,as shown. In Figures 8, 9 and 10 the absence of dotted shading inchamber I33 indicates a partial vacuum condition corresponding to thereduced pressure existing in the engine manifold under differentoperating conditions with the throttle valve less than wide open. InFigure 10 the dotted lines I64 represent magnetic flux to indicate thatsolenoid I42 is energized. The absence of flux I64 in Figu es 8 and 9indicates that the solenoid is not energized.

Figure '1 shows the condition of the system when the engine is at rest.Solenoid I42 is deenergized, atmospheric pressure exists on both sidesof diaphragm "I, and fly weights I59 are retracted by governor springI60 which is stron er than ratio spring 155. Ratio spring I55 is in turnstronger than diaphragm spring I40 to hold ring H4 and shifting leverII5 to the left in its rearmost position. This is the lowest speed,highest torque, position.

When the engine is started and allowed to idle, the reduced pressure inthe engine manifold draws a partial vacuum in chamber I33, causingdiaphragm spring I40, assisted by atmospheric pressure on the rear sideof the diaphragm, to move shifting lever H5 and ring II4 forward todirect drive position against the force of spring I55, as shown inFigure 9. Governor spring I60 is preloaded sufficiently to resistcompression by this additional force, and. since the fly weights I59 donot revolve when driven shaft I2 is not turning, the governor parts willremain in their original condition, but the whole governor is shiftedforward bodily. For idling, the neutral valves are moved forward bylever I24 to return the fluid pumped from chambers 30 to the fluidreservoir in housing I5.

If the car is started slowly by very radually closing neutral valve 90,it may be brought into motion and operated at low speed in direct drivewith the entire control mechanism remaining in its idle position shownin Figure 9. Thus, Figure 9 may be described as illustrating both theidle position and low speed direct drive position of the parts.

In starting with normal acceleration or in starting on an upgrade, themechanism will return from its idling position shown in Figure 9partially or entirely to its Figure 7 position. The first opening of thethrottle concurrently with the loading of the engine by the closing ofneutral valve 90 produces a temporary large increase in manifoldpressure, causing the pressure in chamber 33 to rise almost toatmospheric pressure which exists at all times on the rear side of thediaphragm. This increase in pressure in chamber 33 assisting the ratiospring I55, while the governor weights are still in low speed position,is eifective to compress diphra-gm spring Md and move the shifting leverback to a low ratio position to obtain the necessary mechanicaladvantage for starting and accelerating the car.

The relative spring forces may be selected and adjusted so that when thethrottle is opened wide at low governor speed the shifting lever willmove to its rearmost position, while, if the throttle is opened a lesseramount, the shifting lever will move to an intermediate position toselect a transmission ratio suitable for the loading of the engineimposed by the operator. It will further be apparent that if such astart is made on a steep upgrade the driven shaft I2 will not attainsufiicient speed to throw out the governor weights I 59 against theretractive force of spring I50, the high manifold pressure will be maintained in the chamber I33 and the mechanism will remain in the startingposition shown in Figure 7. It will stay in this position until theshaft I2 finally rotates fast enough to throw out the weights I59, oruntil the manifold pressure is reduced to assist spring I40 to returnthe ratio valve back to direct drive.

When the driven shaft I2 reaches a predetermined speed, the governorweights I59 move outwardly, drawing the plates I51 together andcompressing the governor spring I60, as shown in Figure 8. As thegovernor plates I51 are drawn together, it is apparent that the distancebetween collar I54 and shifting ring H4 is reduced, thereby allowing theshifting lever to move forward to a higher speed ratio position with thesame balance of forces existing between the opposing springs I40 andI55. At the same time, the attainment of a higher running speed peratesto reduce the manifold pressure, thereby allowing diaphragm spring I40,assisted by atmospheric pressure on the rear side of the diaphragm, tomove the diaphragm forward and oppose shaft spring I55 with greaterforce in a new position of balance, since the shaft spring now hasreduced efiective tension because of the compression of governor springI60. The movement of the shifting lever Il5 from its Figure 7 positionto its Figure 8 position is, therefore, gradual and depends upon therate of acceleration of the vehicle and the amount of throttle opening.The parts are proportioned and ad- ,iusted so that they will assumetheir Figure 8 position at a combination of car speeds and manifoldpressures which have been determined to be adequate for the particularengine and the particular automobile, to deliver suflicient power indirect drive. Figure 8, then, representsthecondition of the mechanismunder normal conditions corresponding to so-called high gear or directdrive operation with a gear transmission. If the throttle issubstantially closed and the speed reduced to about the idling speed ofthe engine, the mechanism will move from its Figure 8 position to theFigure 9 position, remaining in direct drive, unless the load reducesthe speed of the engine to a point where the manifold pressure increasessufiiciently to move the diaphragm I3I rearwardly. Then, if the throttleis opened to accelerate, the parts will return to the Figure 7 positionuntil normal direct drive speed is attained again.

' In ascending a steep hill, the diaphragm spring I40 holds thetransmission in direct drive, regardless of increase of manifoldpressure communicated to chamber I33, until the governor slows downsufiiciently to assume a lower speed position. Then, as the governorslows down, the increasing separation of the plates I51 under theexpansion of spring I 60 moves the shifting lever II 5 graduallyrearwardly until a driving ratio is reached where the engine can carrythe load without further slowing of the governor. This action may becontrolled to a considerable extent by the manipulation of the throttle.'If the throttle is opened wider while the governor is slowing down, theincrease of manifold pressure in chamber I33 will then move the shiftinglever sooner, or faster if it has already started to move. In any event,the desired result will be accomplished.

When the vehicle is traveling at a speed above that necessary to holdthe governor in high speed position, as in Figure 8, the diaphragmspring I40 will continue to hold the shifting lever in its forwarddirect drive position even though the throttle is opened wide toaccelerate quickly to a still higher speed. In such condition theincrease of manifold pressure in chamber I33 is insufiicient acting inconjunction with ratio spring I55 to compress the diaphragm spring I40and move the shifting arm to a lower ratio position.

Auxiliary means are, therefore, provided to enable the operator to shiftto a lower driving ratio whenever it may be necessary, in an emergency,even at speeds which would normally call for directdrive. In the presentembodiment, this is accomplished by pressing the foot throttle I44 tothe floor to close switch I43, energizing solenoid I42. The solenoidthen exerts suflicient pull on armature I4I to pull the diaphragm I3Iback to a predetermined intermediate position as shown in Figure 10. Aslong as the switch I43 is held closed, the ratio valves '10 will be heldin an intermediate position to produce the effect in a gear transmissionof shifting back to second gear. The solenoid is made to have a pullwhich may be overcome to return the parts to direct drive after theengine has accelerated sufficiently to establish a fairly high vacuumcondition in the diaphragm chamber. This feature is particularly .usefulin acquiring rapid acceleration to pass other vehicles and to relievethe laboring of the engine on along hill before it has slowed downsufiicienty to shift automatically. Upon opening the switch I43, themechanism immediately returns from its Figure 10 position to its Figure8 position. Y Provision has also been made to meet another contingencywhere conventional fluid transmissions perform unsatisfactorily. '-On aslippery road surface, an automatic transmission may have difficulty instarting the vehicle, because as soon as one rear wheel starts to spinthe transmission proceeds to shift to direct drive, which aggravates thesituation by making the slipping wheel spin faster without obtainingtraction on the roadway. To relieve this situation the present controlmechanism provides means under the control of the operator forpreventing the normal shifting of the transmission into direct drive inresponse to the speed of the shaft 42. By closing a manual switch, notshown, to energize solenoid I50 (Figure 1), the valve I46 is moved tothe rear to close the vacuum line I34 to the engine and vent chamber I33to atmosphere through slot I52. This maintains the condition shown inFigure 7 as long as the throttle is not opened wide, permitting thewheels to be turned slowly and positively at a definite speed, withouttending to race when they slip on the roadway. This feature is useful onicy pavement and slippery mud where positive control of the drivingwheels is advantageous.

I! desired, solenoid I50 may also be energized by throttle switch I43 toadmit full atmospheric pressure in chamber I33 when solenoid I42 isenergiaed in the type of situation described in connection with Figure10. This will reduce the operating force required to be developed bysolenoid 142-.

The transmission and control mechanism of Figure 1 provides threedefinite ratio speeds and direct drive, with smooth change therebetweenobtained by throttling action when the ratio valves 10 are moved acrossthe ports. A greater or lesser number of definite ratio speeds may beprovided by varying the number of sets of motor chambers and reactionmembers, and the transition characteristics may be changed by modifyingthe shapes of the piston elements on valves 10 which are herein shownfor convenience as cylindrical with flat ends.

The present transmission does not provide for reversal of the drivenshaft [2. It is preferred to run the driven shaft 12 into a small gearbox for this purpose, which may be controlled by a manual lever movablebetween forward, neutral and reverse positions.

The embodiment of Figures 11 and 12 Figures 11 and 12 illustrate amodification in which the innermost member is the driving member and theintermediate member is the driven member. The driving shaft is indicatedat 200 and the driven shaft at I. Just ahead of the transmission is astationary plate or frame member 202 having a sleeve bearing 203 tosupport both the shaft 200 and one hub 204 of a rotatable cylindricalhousing 205 which forms the oil reservoir for the transmission. Housing205 has a rear hub 206 supported by a sleeve bearing 201 extending froma stationary frame member 208 whereby the sleeve 20! supports both thehousing and shaft 20l on this frame member. All the rotatable parts turnin the direction of arrow 209 in Figure 12.

Keyed to driving shaft 200 is a rotor or driving member 2|0 having aplurality of forwardly 1nciined slots 2 for blades 2I2. Means forextending and retracting these blades will presently be described.Between the blades are slots containing resilient sealing members 5| ofthe type shown in Figure 5.

The driven shaft MI is integrally connected with a driven member 2|!having cavities definin: three pump chambers 2 l 6 around the drivingrotor 2l0. Between the chambers 2I0 are three partitions of fluidabutments 2 IT, each hav'lhgan arcuate curvature to provide a runninglit with the cylindrical periphery of rotor 210. When the rotor 2 l 0turns in the direction of arrow 20 relative to the driven member 215,fluid is drawn into the three pump chambers 2"; through inlet ports 2I8in the driven member, and discharged through outlet ports 2|! under thecontrol oi ratio valves 220.

Each ratio valve 220 is a balanced piston type valve slidablelongitudinally in a cylindrical bore 22l by movement of an actuatingring 222 as shown in Figure 13. Each valve 220 is arranged to uncoverthree ports 22!, 224 and 225 name valve is moved rearwardly or to theleft in Fig ures 11 and 13, these three being closed when the valve isin the position shown. Adjacent each cylindrical bore HI and 'communieating therewith by a common port 226 is a paral lel cylinder or bore221 containing -a balanced neutral valve 228. Each valve 228 is equippedwith a spring 229 to urge it rearwardly to a closed position, as shown,and these valves are all connected with a common actuating ring 220.

It will thus be apparent that when the driving member 2") is rotatedwith ratio valves 220 in the positions illustrated, fluid from the pumpchambers 2l6 cannot esca e th'roug'h discharge ports 9, and so drivenmember 215 is then compelled to rotate with the driving member by thetorque transmitted through the medium of the hydraulic fluid to produce,in effect, a direct driving connection between driving shaft 200 anddriven shaft 20l. When neutral valve 220 is moved forward, it uncovers aport 23! in a longitudinal discharge passage 232 which is in opencommunication at its ends with the reservoir space within the outerhousing 205. The liquid discharged through outlet ports 2|! can thenflow freely through ports 228 and 23! to permit free rotation of drivingmember 2l0 without exerting any torque on driven member 5. To establisha driving connection with the driven member, the neutral valve 225 mustbeclosed as shown. The port 221a is a relief port for the escape ofleakage fluid from the end or valve cylinder 221, so that the valve willmove freely. This port does not enter into any function of thetransmission.

The ports 223, 224 and 225 constitute inlet ports for the respectivemotor chambers 233, 234 and 235, as shown in Figure 13. Driven member2|! has cavities in its periphery to form these motor chambers when thedriven member is positioned within three reaction members 243, 244 and245. Thus, there are cavities forming three motor chambers 233 withinreaction member 243, cavities forming three motor chambers 234 withinreaction member 244, and cavities forming three motor chambers 235within reaction member 245. Each of these reaction members is equippedwith overrunning clutch dogs I00 engageable with housing 205 as shown inFigure 12 which permit the reaction member to turn in a forwarddirection relative to housing 205, but prevent relative rotation in theopposite direction. When there is no fluid pressure in the motorchambers the reaction members rotate with the driven member. Reverserotation of housing 205 is prevented by similar one-way brake dogs 240mounted stationary frame member 202 and engageable with the hub 204shown in Figure 11.

Driven member 2 l 5 is equipped with a plurality of resilient ring seals248 to enter into 17 engagement with end walls 245 on the reactionmembers. The cross sectional shape of these seals is shown in detail inFigure 14, and Figure is a perspective view of a portion of a sealstraightened out. The seal has a flat bottom surface to seat in its slotand a top sealing surface to wipe the walls 241. The side walls of theseal have cavities 248 with surfaces exposed to the fluid pressure inmotor chambers 233,234 and 235 whereby the body of the seal is com-.pressed by such pressure to raise the top sealing surface out of theslot. The seal relaxes when the pressure is removed from cavities 248.

Housed in individual recesses 249 in each re action member are pivotalblades 250 urged into radial positions by springs 251. Each-blade ismounted on a longitudinal pin 252 extending through the recess 249between the side walls 241 of the reaction member. The reaction-memebers 243 and 245 are similar to the reaction member 244 shown in Figure12, but'the axial-length varies to provide different capacities in thedifferentsets of motor chambers 233, 234 and 235. Between the cavitiesforming these pump chambers the driven member 215 isprovided with threepartitions or fluid abutments 255 in the region of each group of,valves, which partitions have a cylindrical outer surface for a runningfit withinthe reaction members.

Referring to Figure 12, fluid pumped from pump chambers 216 anddischarged through ports 219 and 224 fills the motor chambers 234,causing the pressure to react against blades 256 to drive the drivenmember 2l5forward. The motor chambers all discharge directly into thepreviously mentioned inlet ports; 218 for the pump chambers 216. Thedetails of motor chambers 233 and 235are.the .same as motor chambers 234shown in Figure 12. Additional inlet ports 256 in pump chambers 216provide for drawingoil directly fromthe fluid reservoir in housing 265as may be required to keep thepump chambers .filled.

Thus, when ratio valve 220 is moved rearwardly in the direction of arrow251 in Figure 13.touncover only the port 223, the entire capacity of thethree pump chambers 216 is delivered into the three motor chambers 233,causing the driven member 215 to rotate .slower thanvdriving member 2111When the .port223 is wide open the speed ratio is in accordance with the(relative displacement of the motor and pump-chambers and the torqueratio depends upon the torque increase produced bysthe fluid pressureacting on the additional piston area exposed to the pressure in chambers233. .The opening of the 'motor chambers does notchange the one-to-onetorque ratio always existing between the driving and drivenmembers inthe pump chambers, When the ratio valve 226 is moved farther to bringthe motor chambers 234 into operation, a lower speed ratio and highertorque ratio is obtained, and when'the' valve is moved to itsrearmostrposition to bring all the motor chambers intooperation, thelowest speed ratio with the greatest torque multiplication" is obtained,because then-the-'output of the threepump chambers 216 is dividedbetween the ninemotor chambers in order to drive the'driven member 215forward. Between these definite ratios the change'is smooth throughranges of transition ratios'as in the embodiment of Figures 1- and 2;

*Referringn'ow to Figure--11, actuating ring 222 for the "ratio valve226 is connected with a cross bar26ll on the forward end of a rod261'-extend-- ing through the hollow shaft 201. The rear end of this rodis connected to a cross head 112 on a shifting ring 1 13. The drivingratio of the transmission is controlled automatically by the speed ofthe driven shaft and manifold pressure in conjunction with auxiliarydevices, as explained in connection with Figure 1. Corresponding partsin the control system of Figure 11 are identified by the same referencenumerals used in Figure 1. The actuating plate 2311 for the neutralvalve is moved forwardly in the direction of arrow 258 in Figure .13 bya ring 265 on the inner end of three pins 266 extending forward from aspider 261 on the -hub 266 of the housing. The spider is equipped with arotatable ring 268 engageable by the yoke-onthe lower end of the manualshifting forlgl 24 to moveit longitudinally.

Means will now be described for extending and retracting the rotorblades 212 of driving member 210 by operation of fluid pressure in anovel manner ito r-educe friction"--and;; control the blades. Mounted ondriving shaft 200,1just' within" the frontend wall of housingi 05, is aneccentric or cam 269 extendingover-one hub of driven member215 andarranged to operate a. plurality of auxiliary pumpunitsZ-HJ on thedriven member. Referring now to Figures 18, 19 and 20, each pump 2111hasa pump cylinder 21l containing a piston 212. The piston is urged intoengagement with cam269 by a spring 213 seated in a small chamber 214atthe inner end of cylinder 211. Chamber 214is adjacent a longitudinalvalve cylinder 215 containing a balanced piston valve 216, the chamberand valve cylinder being interconnected at diiferent points by threeports 211, 218 and 219.

When piston. valve 21fi-is in its forward position illustrated inFigures 18 and 19, ports 211 and 219 are closed andiport 218 is open toconnect the chamber 214 with apassage 280 leading to one of thetransmission-pump chambers 216. Ball check valve 281 permits one way.flow in passage. 280 for drawing fluid from the pump chamber 216 whenpump piston 212 moves outwardly in its cylinder. When pump piston 212 ismoved in- 1 wardlyby'the cam 269, fluid is displaced from chamber 21-4through passage 282 communicating .with" an annular-channel 283 at theforwardend of the driving memberzro-tor 210., Ball check valve 284-prevents. return flow through this paspassage. On the rear side ofdriven rotor 210lis another annular channel 285, bothof these channelscommunicating withthe bottoms of all the blade slots 211. aroundthe'rotor, as. shown in Figure 114- Apassage-286 containing a'ballcheckvalve 281 connects the. annular channel.285-,with the reariside ofthepump chamber 216 which is in communication'with the suctionpassage280. Thus :thefluid pumpediby piston 212 through passage 282 is forcedinto the bottoms of the blade slots to-extendthablades 212 when valve.-216 .-is in its forward position. Thespring tension on ball 'checklvalve-281 is adjusted to maintain a slightly higher pressure in; thebottoms of .the blade slots 21 1 than exists in thepumpchambers 216, sothat, regardless of wide variations of fluid pressure in'pump; chambers216; the same pressure differential is maintained to extend the bladestThis arrangement insures that the blades will be extended, no matter howhigh the pressure inpump'chambers 216 may rise, "and automaticallyreduces the pressure under the blades when the pressure in pumpchambers-216 falls to a low valuerto avoid unnecessary friction on theends of-'the-blades-.-'-

When'piston valve 2164s movedto its rear-posttion, as shown in Figure20, suction passage 280 is closed and a passage 288 leading to theannular channel 283 is connected with port 211. Passage 288 contains aball check valve 289 to permit suction through this passage for the pumppiston 212 while preventing discharge through the passage. In the rearposition of piston valve 216, port 219 is connected with a dischargepassage 290 communicating with the reservoir space in housing 205. Thedischarge passage includes a ball check valve 291.

Thus, when piston valve 216 is in the rear position shown in Figure 20,the pump piston 212 operates to withdraw fluid from the bottoms of bladeslots 211, creating a vacuum condition under the blades to hold themfully retracted in the bottoms of their slots so they will not dragagainst driven member 215. With the blades retracted in this manner,mechanical wear is eliminated, and the pumping action of driving rotor 2I is suspended to place the transmission'in neutral independently ofvalve 228 in Figure 13.

Each piston valve 216 is normally held in its forward position by aspring 292. The valves 216 for the several auxiliary pumps 210 haveactuating stems extending out through the pump housings 210 forengagement by an actuating ring 292 carried by sliding pins 293 inhousing 205, as shown in Figures 11 and 18. The forward ends of pins 293are engaged by a ring 294 carried by the plungers or armatures 295 of aplurality of solenoids 296 mounted on frame member 202.

When the transmission is in normal driving operation, the solenoids 296are deenergized, and there is a slight clearance between the actuatingrings and pins just described. When solenoids 296 are energized, theplungers 295 carrying the ring 294 are extended rearwardly to push theinner actuating ring 292 against the stems of piston valves 216 to movethese valves to blade retracting position as shown in Figure 20.

In Figure 11 the diaphragm 131 and governor 156 are shown in idlingposition, as in Figure 9. This position may also be assumed in directdrive at very low speeds under light load with the throttle closedsubstantially to idling position. Figure 16 shows the governor andshifting lever H in direct drive position at normal speed as describedin connection with the diagram in Figure 8.

Figure 1'7 corresponds to diagrammatic Figure 10, in which the shiftinglever is pulled rearwardly by the action of solenoid 142 for anemergency or temporary lower ratio drive, notwithstanding the fact thatthe governor weights are thrown out to their high speed position andthat a partial vacuum condition exists in diaphragm chamber 133. Asexplained in connection with Figure 10, the position shown in Figure 17is maintained only so long as switch 143 in Figure 1 is held closed bythe throttle pedal 144, and until the engine has acceleratedsufficiently to establish a predetermined vacuum condition in thediaphragm chamber.

Embodiment of Figures 21 and 22 A third embodiment of the invention isillustrated in Figures 21 to 23 for transmitting power from a drivingshaft 300 to a driven shaft 301 in different speed and torque ratios.Here the driven member is outermost and the intermediate member is thedriving member. The driving shaft carries a driving member 302 keyedthereto for rotation between two parts of a driven member 303 which isintegral with the driven shaft. Driven member 303 constitutes acylindrical housing for the transmission and a reservoir for thetransmission fluid. The driven shaft and driven member are supported ina bearing 304 in a stationary frame member 305 at the rear end of thetransmission. Other parts of the transmission are supported by a tube orsleeve 306 mounted on a frame member 301 at the front end of thetransmission. Driven member housing 303 has a hub 300 on its front endsupported on the outside of sleeve 308, and driving shaft 300 issupported in a bearing 309 within the sleeve 306. The rear end ofdriving shaft 300 is further supported and maintained in alignment withthe driven shaft by a pilot bearing 310. The rotating members all turnin the direction of arrow 311 in Figure 22.

The outer part of driven member 303 is provided with three cavitiesforming pump chambers 315 symmetrically distributed around the housingand separated by partitions 31G forming fluid pressure abutment betweenthe chambers. The partitions 315 have cylindrical inner surfaces with arunning fit on the driving rotor 302. Pump chambers 315 are providedwith inlet ports 311 to draw fluid from the reservoir chamber within thehousing 303, and outlet ports 310 leading to valve chambers.

Driving member 382 comprises a slotted rotor having blades 320 urgedoutwardly against the surrounding housing of driven member 303 bysprings 321. For convenience in illustration, outlet ports 318 are shownin Figure 22 at the opposite ends of the pump chambers 315 from theinlet ports 311. Upon relative rotation of the driving rotor 302 withinthe driven member 303, which forms in effect a pump casing therefor, thefluid drawn in through each port 311 is swept through chamber 315 andout of the outlet port 318.

Driven member 333 has radial walls 322, as shown in Figure 21, definingthree sets of motor or reaction chambers 323, 324, and 325 in an innerpart of the driven member. These three sets of chambers contain threereaction members 333, 334 and 335. Each reaction member is equipped withoverrunning brake dogs 5-5, as in Figure 2, engageable with stationarysleeve 38 to permit forward rotation of the reaction men.- ber andprevent reverse rotation. Each reaction member is also equipped withblades 55 urged outwardly by springs 51 to sweep the motor chambers, asshown in Figure 22 in the case of central motor chambers 324. Betweenthe blades 55 are seals 51. The blade slots 56 are also equipped withgrooves 58 to introduce the fluid pressure to the bottoms of the bladeslots, as explained in connection with Figure 2. The motor chambers,such as chambers 324, are formed by cavities in the inner part of drivemember 303, shown in elevation in Figure 22 between driving member 302and reaction member 334. Between these cavities are partitions 336 witha cylindrical curvature to have a running fit around the three reactionmembers.

In the region of each partition 336 in drive member 303 there is a valveassembly as shown in Figure 23. Each valve assembly comprises fourlongitudinal bores or passages 331, 338, 339 and 340 in the inner partof driven member 303. The bore 340 constitutes a cylinder for a balancedpiston valve 341, and the bore 338 constitutes a cylinder for a balancedpiston valve 342, the former being the ratio valve and the latter beingthe neutral valve to function in general as in the previous embodiments.

The bore 339 constitutes a fluid pressure chamber which is always incommunication with the outlet passage 3i8 of an adjacent pump chamber si 5. When the ratio and neutral valves 34! and 342 are in the forwardpositions illustrated, there is no escape of fluid from chamber 339 andvalve cylinder 343, and so driven member 393 is constrained to rotatewith drivin member 382 to establish, in effect, a direct drivingconnection between the driving and driven shafts. The reaction membersthen rotate with the driven member.

The motor chambers 323, 32s and 325 are connected by the respectiveports 343, 344 and 335 with the ratio valve cylinder 34%, and thiscylinder is in turn connected with pressure chamber 339 by the two ports346 and 341. Thus, as the ratio valve piston 3 is moved to the rear,first the port 343 and then the port 344 is opened to admit fluid fromthe pump chambers tie into the motor chambers 323 and 32d to applyadditional torque to the driven member in accordance with the pressureand piston areas in the motor chambers Further movement of ratio valve34! to its rearmost position places port 335 in communication with portB ll to admit fluid also to the third set of motor chambers 325. Themotor chambers dis charge through open outlet ports 325. The speed andmechanical advantage of driven member 303 with respect to driving member5562 thereby depend upon the position of ratio valve 3M which controlsthe number of motor chambers to be opened to receive the output of thepump chambers. When the ratio valve 34! is in its rearmost position, allnine motor chambers are opened to receive the pump output, and thetransmission is in its lowest speed and highest torque ratio drive. Asthe ratio valve moves across the ports it exerts a throttling actioncontrolling the motor chamber pressure to produce a smooth change in thespeed and torque ratios throughout the whole range of the transmission.Regardless of the additional torque obtained from the motor chambers thefull value of the input torque is always transmitted directly to thedriven member in the pump chamhere.

The longitudinal bore or passage 331 is open at its ends into the fluidreservoir within housing 333. A port 338 connects this passage withvalve cylinder 338, and another port 343 0011-- nects cylinder 338 withpressure chamber 339. Thus, when neutral valve 342 is moved to the rear,these two ports are brought into communication so that fiuid deliveredto chamber 339 from the pump chambers 3l5 is passed back to the fluidreservoir without going through the motor chambers and withoutdeveloping a pressure in the pump chambers. This establishes a neutralfor the transmission in which driving member 392 may rotate withindriven member 333 without transmitting torque to the latter.

Ratio valves Sill are connected with an actuating ring 3%, and neutralvalves'342 are connected with an actuating ring 35L The parts are shownin their forward or direct drive position in Figures 21 and .23, therearward motions of the parts hereinabove referred to being in thedirection of arrow 352 which applies to both valves.

The actuating ring 353 for the ratio valves may be pressed rearwardly bya series of pins 354 carried by an external actuating ring 355. Theactuating ring 35! for the neutral valves carries a series of pins 356extending outthrough the housing 333 for actuation by a second .externalring, not shown. These actuating rings may be operated by manual orautomatic mechanism as shown in the first two embodiments or in anyother suitable manner, as will be readily understood by personsskilledin the art.

When. one or more of the ports 343, 344, or 345 is closed, thecorresponding reaction members 333, 334 or 335 are free to rotate in aforward. direction with driving member 332 to prevent unnecessaryfriction on the reaction member blades and motor chambers, and also torelieve the vacuum drag on the driven members. [is soon as one oftheseinlet ports is opened by ratio valve 3 the fluid reaction in theactivated motor chambers holds that reaction member stationary againstits one-way brake dogs 25 as an abutment and exerts a driving torqueupon the inner part of the driven member. Thus there is relative motionbetween the reaction members and the driving member only when a ratiolower than direct drive is called for, and then only in the case ofthose reaction members which are in activated pump chambers.

A common advantage of all the illustrated embodiments of the inventionis that in direct drive no fluid is pumped and there is no relativemovement of the parts to cause losses or wear. In any lower ratio drive,the rate of fluid pumping is proportional to the torque increasedemanded of the transmission, rather than the total output torque sincethe full input torque is applied directly to the driven member. Fluidfriction losses affect the operating efficiency of the transmission onlyin those intervals when direct drive will not satisfactorily carry theload. At such times the losses, also, are a function of the torqueincrease rather than the total output torque, because of the directapplication of input torque to the driven member. The transmissionresponds to an increase in torque demand by pumping enough fluid toproduce the additional torque without changing the constanteffectiveness of the one-to one torque ratio drive through the medium ofthe fluid interposed between thedriving and driven members in the pumpchambers. To supply the additional torque there must be relativemovement between the driving and driven members, which requires eitherthe driving member to speed up, or the driven member to slow down. Theonly fluid friction losses are those involved in the pumping of thefluid to produce this additional torque over the one-to-one ratio valuewhich is transmitted directly by the fluid pressure in the pumpchambers.

The use of three pump chambers and three motor or reaction chambersdistributed symmetrically around the shafts makes the device more.compact, hydraulically balances the working parts and reduces theworking pressure of the fluid to one-third the pressure that would berequired to transmit the same torque in a single working chamber of thesame size.

Having now described my invention and in what manner the same may beused, what I claim as new and desire to protect by Letters Patent is:

l. A fluid transmission comprising a driving member, a driven member anda plurality of reaction members all mounted for concentric rotationinone direction, said driving and driven members co-operating with eachother to form pump chambers. .therebetween, one of saidfirst two membersadditionally co-operating with said reaction members to form motorchambers, overrunning brake means operative on said reaction membersindividually to prevent reverse rotation of said reaction members, andfluid passages and valves to control a flow of fluid from said pumpchambers to a variable number of said motor chambers.

2. A. fluid transmission comprising a driving member and a driven membercooperating with each other to form pump chambers therebetween, aplurality of reaction members mounted for individual rotation in thedirection of rotation of said driving member and all cooperating withone of said first mentioned members to form motor chambers between eachreaction member and said other member, overruning brake means operativeon said reaction members individually to prevent reverse rotation ofsaid reaction members, and fluid passages and valves to control a floivof fluid from said pump chambers to said motor chambers.

3. A fluid transmission comprising concentric driving, driven andreaction. members, there being a plurality of reaction members arrangedin end to end relation and mounted for individual rotation in thedirection of rotation of said driving member, overrunning brake meansoperative on said reaction members individually to prevent reverserotation of said reaction members, said driven member being disposedbetween said driving and reaction members, said driven membercooperating on one side with said driving member to form pump chamberstherebetween and cooperating on its other side with said reactionmembers to form motor chambers, and fluid passages and valves to controla flow of fluid from said pump chambers to said motor chambars.

4. A fluid transmission comprising an annular driven member, said drivenmember having inner and outer peripheral working portions, a concentricdriving member cooperating with one of said peripheral portions to formpump chambers between said driving and driven members, and a pluralityof reaction members concentric with said driving and driven members andcooperating with the other peripheral working portion of said drivenmember to form a plurality of motor chambers, said reaction membersbeing arranged in end to end relation and mounted for indivi ualrotation in the direction of rotation of said driving member,overrunning brake means operative on said reaction members individuallyto prevent reverse rotation of said. reaction members, and fluidpassages and valves to control a flow of fluid from said pump chambersto said motor chambers.

5. A fluid transmission comprising a driving member, a driven membercooperating with said driving member to form a positive displacementpump, a plurality of reaction members cooperating with said drivenmember to form positive displacement motor chambers, said members beingconcentric, said reaction members being mounted for individual forwardrotation and equipped with an overrunning brake to prevent reverserotation, and fluid passages and valves to control a flow of fluid fromsaid pump to a variable number of said motor chambers.

6. A fluid transmission comprising a driving member, a driven membercooperating with said driving member to form pump chambers between saidmembers for transmitting torque directly to the driven member inaccordance with the fluid pressure in said chambers, a plurality ofindividually rotatable reaction members cooperating with said drivenmember to form motor chambers between said members for transmittingadditional torque to said driven member in accordance with the fluidpressure in the motor chambers, passages for delivering fluid from saidpump chambers to said motor chambers, a valve in said passages operablein one position to prevent discharge of fluid from said pump chambersand operable in other positions to admit fluid to a selected number ofsaid motor chambers, and overrunning brake means operable on saidreaction members individually to provide an abutment against reverserotation of the reaction members.

7. A fluid transmission comprising a driving member, a driven member anda plurality of individually rotatable reaction members,said drivenmember forming with said driving member a fluid pump, and said drivenmember forming with each of said reaction members a separate fluid motorto receive fluid from said pump, valve means to control the number ofsaid motors receiving fluid from said pump, and overrunning brake meansoperable on each reaction member to permit rotation of the reactionmembers with the driven member and to prevent reverse rotation of thereaction members.

8. A fluid transmission comprising rotatable driving, driven andreaction members, there being one driving member, one driven member anda plurality of reaction members, said driving driven members forming afluid pump, and each or" said reaction members forming with said drivenmember a separate fluid motor for said driven member, means to directfluid from said pump selectively into one or more of said motors and toshut off discharge from said pump to lock the driven member to thedriving member, said reaction members being individually rotatable inthe direction of rotation of the driving member, and individual means toprevent reverse rotation of each of said reaction members.

9. A. fluid transmission comprising rotatable concentric driving, drivenand reaction. members, there being one driving member, one drivenmember, and a plurality of reaction members individually rotatable inthe direction of rotation of said driving member, pump chambers betweensaid driving and driven members, separate motor chambers between saiddriven member and each of said reaction members, overrunning brake meansoperative on each of said reaction members to prevent reverse rotationof the reaction members, and a ratio control valve to admit fluiddischarged from said pump chambers into selected ones of the motorchambers.

10. A fluid transmission comprising balanced rotatable concentricdriving, driven and reaction members, there being one driving member,one driven member and a plurality of reaction members, the outermost ofsaid members constituting a fluid housing and reservoir for thetransmission, said driving and driven members constituting a fluid pump,said driven member co-operating with said reaction members to form aplurality of fluid motors, outlet passages in said pump, inlet passagesin said motors, valve means for controlling the flow of fluid throughsaid passages between said pump and motors to supply a variable numberof said motors, and means including valves and passages for divertingfluid discharged from said pump into said reservoir to relieve the pumppressure.

